Delete submission

I have a warning from you that I have 450 submissions stored, I only want to store say the past 50 submissions, is that possible?

Yes, you can delete the submission. Keep in mind that once deleted, it is not recoverable. Here's a guide: How-to-Delete-Form-Submission-Data

If you want you can download the submissions before deleting it. Here's the link: How-to-Download-Form-Submissions-as-Excel-CSV-PDF

Hope that helps.